Biomarkers for Early Diagnosis of AKI in Critically Ill Patients

New Orleans—Hospitalized patients may experience acute kidney injury (AKI), a condition that is more common among patients in the intensive care unit (ICU). Serum creatinine measurement can be used to assess AKI; however, according to Luana A. Pedroso, MD, and colleagues, serum creatinine is a poor and delayed marker of AKI. In recent decades, new circulating and urinary biomarkers have emerged as promising in the early diagnosis of AKI, offering better sensitivity and specificity profiles.

The researchers recently conducted a study to conduct a systematic review of literature that evaluated the performance of biomarkers for the early diagnosis of AKI. They reported results during a poster session at 2017 Kidney Week in a poster titled Use of Biomarkers in the Early Diagnosis of AKI in Critically Ill Patients: Systematic Review.

The review included experimental and observational studies published in MEDLINE, BVS [Brazil], CINAHL (Cumulative Index to Nursing and Allied Health Literature), and EMBASE between 20006 and 2016. Patient populations of interest were adults ≥18 years of age admitted to the ICU.

Following application of inclusion and exclusion criteria, eight studies were selected. The biomarkers investigated were neutrophil gelatinase-associated lipocalin, L-type fatty and binding protein, N-acetyl glucosamine, and cystatin C. In 66.7% (n=16/23) of tests performed in the studies, analyses used urine samples.

The biomarkers with the highest sensitivity and specificity profiles were the heat shock protein-72 (sensitivity=100% and specificity=90%) and interleukin 18 (sensitivity=92% and specificity=100%). In two studies, cystatin-C demonstrated poor performance. Two studies presented results that were unfavorable for the use of biomarkers for early diagnosis of AKI due to their levels being significantly affected by comorbidities, even in the absence of AKI.

“All biomarkers have suffered some influence of other factors, such as comorbidities or etiology of AKI. An understanding of a single biomarker is unable to help identify the etiology and mechanisms of AKI. Thus, the use of a diagnostic kit combining different biomarkers could be suggested for early diagnosis of AKI. Besides, the identification of AKI etiology may be helpful to guide the implementation strategies,” the authors said.

Source: Pedroso LA, Nobre V, De almeida CD, et al. Use of biomarkers in the early diagnosis of AKI in critically ill patients: systematic review. Abstract of a poster presented at the American Society of Nephrology 2017 Kidney Week, November 4, 2017, New Orleans, Louisiana.